The present invention is directed to a hand-held tool, such as a drilling tool, a powered screwdriver and the like, with a chuck for holding a tool bit removably secured on a rotating spindle. The chuck includes a driver socket at one end with openings for radially displaceable locking members. The driver socket is encircled by a rotatable support ring for retaining the locking members in recesses in the rotating spindle.
In hand-held tools, the chuck is subjected to high stresses and is usually detachably connected with the rotating spindle so that it can be easily replaced or repaired.
In the case of less complicated hand-held tools, the connection of the chuck is effected by screw threads. In actual operation, however, a screw thread can become tightened to such an extent that it cannot be loosened without the use of another tool. In hand-held tools, where the rotational direction can be reversed, such as in powered screwdrivers or the like, the screw thread can become loosened during operation. In other known hand-held tools, such as in DE OS No. 33 10 371, the chuck is secured on the rotating spindle by radially displaceable locking members. The locking members engage within recesses in the surface of the rotating spindle and are held against radial disengageeent by a support ring surrounding the driver socket. When the support ring is rotated for the removal of the chuck, the locking members shift into cutouts in the support ring. Such a connection type has the disadvantage that it is not free of play and the driver socket can move axially for a limited amount and rotate relative to the rotating spindle, unless additional securing means which involve an extra expenditure, such as special screws, are utilized.